Lawrence Krauss dialogued (if that term is appropriate) with William Lane Craig in Australia this September (2013). Krauss produced an edited email from Alexander Vilenkin which Krauss claimed shows that the BGV theorem does not demonstrate that the universe (or multiverse) has an absolute beginning. The unabridged letter can be seen at Craig's website under Q&A #336 http://www.reasonablefaith.org/honesty-transparency-full-disclosure-and-bgv-theorem. Vilenkin had in 2006 claimed that the theorem proves there must be an absolute origin to the universe/multiverse. Now he says that the possibility of a quantum gravity regime where classical concepts of time and causation are no longer applicable would make it possible that this claim is no longer applicable. At least that is my understanding of his statement.

Craig has his take on Vilenkin's statement (see the above link) but I wonder if anyone knowledgable of this area of physics might be able to comment as well. I have some very specific questions and I could give exact quotations.

I am not at all an expert in cosmology, even though I have a couple papers in the field as an undergraduate. And I have not watched the Krauss/Craig debates. But I do have a few thoughts about the BGV theorem and its applicability in apologetics. It is indeed important for those who debate it to know what the theorem says, and Craig has sure done his homework; it appears to me from a cursory reading of the fallout from the debate that he has done a better job than Krauss. But I note that it is a "theorem" - that is, a particular result within a particular framework of mathematical cosmology. True, it does not depend on Einstein's theory of general relativity specifically, but it is in my view essentially a statement in mathematics. Like any physical theory, or mathematical theorem, it is limited in its domain of applicability. The BGV theorem makes it more difficult for someone to hang on to a universe which has always existed, and in this way perhaps strengthens the case for a finite time history of the universe (and, so the story goes, hence the case for a creator). Carroll has often reminded us, though, that Aquinas showed that even an eternal universe still "needs" a creator. (See for example "Aquinas and Contemporary Cosmology: Creation and Beginnings" in Astrophysics and Space Science Library Volume 395, 2012, pp 75-88; online here .)